1. Field of the Invention
The present invention relates to a toggle type parking brake lever apparatus adapted to be used in industrial vehicles such as a forklift or the like.
2. Description of the Prior Art
FIG. 10 shows a typical conventional toggle type parking brake lever apparatus in which a brake lever 1 is journalled to a lever bracket 3 secured to a machine frame 2 at the front part of a cabin. This lever bracket 3 is formed therein with an elongated hole 4 which extends toward the pivot point of the brake lever 1, and along which a hook 5 is movably held. The hook 5 is connected with the forward ends of brake wires 6 which are in turn connected to a brake main body (not shown). A link 7 is connected between the intermediate section of the brake lever 1 and the hook 5 so as to constitute the so-called toggle mechanism in cooperation with the brake lever 1. Accordingly, when the brake lever 1 is manually turned from a brake release position (which is a forward tilted position as indicated by the dotted chain line) to a brake application position, an upright position indicated by the solid line, which slightly exceeds the dead center point D. P. of the toggle mechanism, the hook 5 is pulled toward the brake lever 1, causing the brake wires 6 to be towed and therefore applying the parking brake.
The above-mentioned parking brake apparatus provides an advantage such that a stable braking force can be ensured by manually turning the brake lever 1 to the brake application position. However, the holding of the lever in this apparatus can only rely upon a turning moment which is applied to the brake lever 1 by the reaction to the towing force of the brake wires 6 which is effected when overriding the dead center point. Accordingly, if an external force is exerted to the brake lever 1, being caused by an unexpected accident such as an erroneous manipulation by the driver or the like, so that the brake lever 1 is moved in the brake releasing direction, reversely overriding the dead center point, the brake lever 1 is automatically and continuously turned to the brake release position by the above-mentioned reaction to the towing force, resulting in release of the parking brake.